Information and interactive services available to mobile vehicles are increasing due to the demand of mobile vehicle operators for services such as navigation assistance, directory assistance, vehicle maintenance assistance, roadside assistance, information services assistance and emergency assistance. Requests for many of these services occur when a vehicle is outside of a home region, for example, during personal travel or business trips to neighboring or distant cities. In addition, the number of vehicles outfitted with suitable equipment to request and receive service information is growing.
Transmission of data and voice information to and from a mobile vehicle requires at least a portion of the communication system to be a wireless link. This link may be shared with many other mobile vehicles as well as many cellular phone users not in mobile vehicles. With the proliferation of mobile phones for personal use and for mobile vehicle assistance, a preferred cellular service carrier may be unable to meet the needs of all the clients and subscribers. Requests for mobile phone connections may be detrimentally impacted due to the unavailability of transmission channels during times of high usage, or limited service access in certain markets. Call requests may be deferred to non-preferred carriers, or may be denied altogether. Consequently, there may be times when service with a preferred carrier is not available, or service may not be available at all.
Service requests from mobile vehicles may occur often while roaming outside of local calling areas. Mobile phones may not receive adequate priority for cellular service access when outside the home service area. One or more wireless carriers may be capable of providing wireless connections to the mobile vehicle while roaming, however, the carriers may not have a contract for providing service to the mobile vehicle in that geographical area. If there are no contract wireless service providers in an area, then a wireless connection may be unobtainable or require a premium payment.
Mobile vehicles may reside in and cross multiple market areas, with access requests possible in each market area. As a vehicle traverses through one cellular region to another, multiple carriers may be utilized. A mobile vehicle may not have service contracts in place with each carrier, and excessive charges may be applied when accessing non-preferred carriers.
Provisions for continued services to roamers may require an allocation of voice channels that a carrier in a particular geographical area may prefer to reserve for subscribers in the home region. As a result, a mobile vehicle may not get a connection with a carrier due to the unavailability of channels. A carrier in a particular market may allocate channels for use by other preferred roamers in the area, possibly preventing an unaffiliated mobile vehicle from receiving services within the particular market.
In cases where a cellular phone user is unable to obtain a wireless connection with a primary contract carrier, the user may be given a message that no service is available and left to his/her own means to procure services with another carrier. A mobile vehicle may benefit from having a means for automatically locating services with a secondary carrier within the same band and using the same acquisition technology as the primary carrier. The secondary carrier could be, for example, in an analog cellular band such as 800 MHZ cellular rather than a PCS band nominally at 900 MHz or 1900 MHz. The secondary carrier also may be employing a different technology such as TDMA, for example, rather than CDMA or vice versa. When the secondary carrier is not within the same band, it would be desirable to methodically switch and search for a secondary carrier outside of the primary band. When outside of the home market region, it also would be desirable to employ a secondary carrier that is a preferred contract carrier and avoid unnecessary premium charges. It would also be desirable to automatically determine a preferred primary or secondary contract carrier based on the geographical region where the mobile vehicle is currently located. Cell phone functions such as registration and call origination may then be done with a preferred contract carrier.
In situations where a mobile vehicle urgently requires a cellular phone connection, a fallback position may be desirable. A fallback position might include the use of a selected phone number that receives high priority service by multiple carriers. Another fallback position might include the use of the well-established analog mobile phone system in conjunction with a widely recognized phone number for high priority service.
It is the object of this invention, therefore, to provide a method for establishing a wireless service connection for a mobile vehicle to a cellular network, using preferred carriers and procedures depending on the geographical region in which the mobile vehicle is located, and overcoming the deficiencies and obstacles described above.